1985 Chevy El Camino

I just bought this 85 El Camino last week. It cranks instantly, and runs real good. It got cold this week, and on first start up when its cold outside it puts out huge clouds of white smoke (?). I am not sure it is smoke, because it disipates very quickly into the atmosphere. It lasts about a minute and a half then quits and does not do it again until the engine is cold and the temp is cold outside. Then it will do it again, for only a minute and a half.